Article comprising ionomer and polyamide

Abstract

A multilayer structure comprises a surface layer, a substrate, and optionally additional layers wherein the surface layer comprises or is produced from a blend comprising an ionomer and a polyamide; the ionomer is or must be derived from at least three repeat units derived from ethylene, an α,β-unsaturated C3-C8 carboxylic acid, and a dicarboxylic acid or its derivative; and the dicarboxylic acid or its derivative is maleic acid, fumaric acid, itaconic acid, maleic anhydride, fumaric anhydride, itaconic anhydride, maleic acid monoester, fumaric acid monoester, itaconic acid monoester, or combinations of two or more thereof.

Description

[0001]This application is a continuation in part of application Ser. No. 10 / 861,973, filed Jun. 4, 2004, now pending, which claims priority to provisional application 60 / 475978, filed Jun. 5, 2003; the entire disclosures of the Ser. No. 10 / 861,973 and 60 / 475978 applications are incorporated by reference.[0002]The invention relates to articles comprising a top or surface layer of a composition of ionomer and polyamide wherein the top is scuff- and / or scratch-resistant, transparent decorative, and protective.BACKGROUND OF THE INVENTION[0003]Polymer films are being used more frequently for surface decoration and protection instead of coatings. For example, polymer film decorations increasingly provide freedom of design, lower cost and are environmentally more compatible than the conventional coating process. The surfaces of many sports and industrial articles are designed with protective and decorative films. Many applications demand new materials with excellent processability, mechani...

AI Technical Summary

Benefits of technology

[0016]the dicarboxylic acid or its derivative is maleic acid, fumaric acid, itaconic acid, maleic anhydride, fumaric anhydride, itaconic anhydride, maleic acid monoester, fumaric acid monoester, itaconic acid monoester, or combinations of two or more thereof;

[0017]the acid moiety or a portion thereof in the ionomer is neutralized with one or more metal ions;

[0018]the polyamide is derived from one or more lactams or amino acids and is not a polycondensation product of diacids and diamines; and

[0019]the substrate can be a film or sheet comprising or derived from polyvinyl chloride, ethylene vinyl acetate copolymer, ethylene propylene diene (EPDM) elastomer, polypropylene, ethylene copolymer, cellulosic material, wood fiber, ionomer, polyamide, polyester, polyurethane, styrenic polymer, acrylonitrile-butadiene-styrene copolymer, or combinations of two or more thereof.

Problems solved by technology

Because of their relatively low melting temperature, ethylene copolymer ionomers can be particularly vulnerable to scuffing.

This may result in insufficient scuff resistance of ionomers in everyday use and greatly limits the use of ionomers in more demanding applications.

The disadvantages of this process include its two-step nature (processing and imbibing) combined with the toxic nature of diisocyanates.

The shortcomings of this approach consist of increasing crystalline regions in the polymer that lead to reduced clarity while providing only a modest increase in melting temperature and therefore scuff resistance.

Also, scratch resistance suffers significantly.

Either they are limited in effectiveness by the inherent melting temperature of polyethylene or they add significant cost or feasibility problems to the processor and / or end user of the ionomer sheets and films used for protective applications.

Polyamides, particular nylon-6, are engineering polymers that can be used for many applications, but they cannot be used for decorative and protective film applications.

Mixing of polyamide and ionomer such as those described in U.S. Pat. No. 3,317,631 leads to blends with good scratch resistance and other surface properties but with very poor optical properties (i.e. opacity).

Poorly dispersed and / or large particles tend to scatter rather than transmit light.

As a result the polymer blends tend to be opaque.